Semiconductors are usually manufactured using various photolithographic techniques. The circuitry used in a semiconductor is reproduced from a reticle onto a semiconductor chip. This reproduction is often accomplished with the use of optical systems. The design of these optical systems is often complex, and it is difficult to obtain the desired resolution necessary for reproducing the ever decreasing size of components being placed on a semiconductor chip. Therefore, there has been much effort expended to develop an optical reduction system capable of reproducing very fine component features in the order of 0.35 and 0.5 microns. In order to accomplish this, it is often necessary for the optical system to operate with short wavelengths of light deep in the ultraviolet region of the spectrum.
One such optical system is illustrated in U.S. Pat. No. 4,953,960 entitled "Optical Reduction System" issuing to Williamson on Sep. 4, 1990, which is herein incorporated by reference. While the optical system disclosed therein performs adequately for the intended purpose, it is not well adapted to use with longer wavelengths as used in other semiconductor manufacturing applications. Therefore, there is a need for an optical system having good correction when used in photolithography for manufacturing using a broader band wavelength, including the I-line band of the mercury spectrum.